1. Field
The present invention relates to an integral label-free biosensor capable of detecting a biomolecule, and an analysis method using the same, and more particularly, to an integral label-free biosensor, which is capable of qualitatively and quantitatively analyzing a biomolecule by integrally integrating a light source, a photoetector, an optical waveguide, and a microcantilever on a silicon substrate, and an analysis method using the same.
2. Discussion of Related Art
A biosensor is a sensor configured by a bioreceptor and a signal transducer to selectively detect a biomaterial which is to be analyzed.
The bioreceptor includes enzyme, protein, an acceptor, a cell, a tissue, DNA, and the like, which may selectively react to and be selectively combined with a specific biomaterial, and various physiochemical methods, such as an electrochemical method, a fluorescence method, an optical method, a color developing method, and a piezoelectric method, are used as a signal transducing method.
The biosensor is applied to an environment field used for measurement of phenol of waste water, heavy metal, agricultural pesticides, phosphide, and a nitrogen compound, and an analysis of residual agricultural pesticides of food, antibio, and an infectious agent of disease, as well as a sensor field for an early diagnosis or monitoring of various diseases, such as blood sugar, diabetes, cancer, and myocardial infarction, and an application field thereof is a very broad and significant technical field which is up to sensors for military, industry, and research fields.
A signal transducing method used as a method of detecting a biomaterial may be generally divided into two methods, an electrochemical method and an optical method.
The electrochemical method needs to convert a reaction of a biomaterial into a measurable electric signal by using a device, such as an amplifier, in order to detect a minute electric signal generated by a reaction of the biomaterial existing in a sample, such that there is a disadvantage in that equipment and a circuit configuring the biosensor are complex, and used electronic equipment is expensive. Further, since the great number of ions having charges are present in a sample of a body fluid (blood, urine, tear, and the like) including a biomaterial, which is to be analyzed, and the ions have the possibility of influencing an electric signal of the biosensor, the electrochemical method has a limitation in manufacturing a biosensor having excellent selectivity and sensitivity.
By contrast, the optical method is a method of analyzing existence of a biomaterial and a concentration of a biomaterial by converting an optical signal generated from the biomaterial by using a light source and a photodetector, and has an advantage in that it is relatively simple to configure the biosensor and ions having charges existing in a sample less influence an electric signal of the biosensor compared to the electrochemical method, so that the optical method is widely used in a high sensitive biosensor.
In the optical method of detecting a biomaterial in the related art, an optical biosensor for labelling a bio-antibody with a fluorescence material emitting light and the like, detecting a bio-antigen corresponding to the bio-antibody, and calculating the amount of concentration of the bio-antigen, which is to be detected, in proportion to an intensity of fluorescence measured by the biosensor is generally and widely used.
Further, recently, research and development on optical biosensors, such as a surface plasmon biosensor and an optical waveguide biosensor, as a label-free biosensor, which does not use a label material, such as a fluorescence material, has been actively conducted.
The optical biosensor is configured by an external light source for generating light and a photodetector for measuring an optical signal. A laser element is used as the light source for generating light, and a spectrometer is used for detecting an optical signal.
Since the laser device used in the optical biosensor is generally manufactured by using a compound semiconductor thin film, it is difficult to grow a high quality compound semiconductor thin film, and cost for growing a thin film and manufacturing a device is very high. Further, since the compound semiconductor thin film used for manufacturing the light source in the related art is grown on a non-silicon based substrate, it is not easy to integrate the compound semiconductor thin film with a silicon electronic device for configuring a peripheral electronic circuit. Further, since the optical biosensor configures the sensor by using the external light source and the photodetector, the optical biosensor is very complex and requires a precise optical system, and thus there are many disadvantages in that it is difficult to manufacture a small biosensor, mass-produce a biosensor, and manufacture a low-price biosensor.